Brown vat-dye.



Y UMTED STATES A E orricn ALBRECHT SCHMIDT, OF HGGHST-ONJPHE MA IN,GERMANY,- ASSIGNOR TO FARBWERKE VORM. MEISTER. LUGIUS 5; BRUNING, OFHOCHST ON-THE-MAIN, GERMANY, A CORPO- RATION OF GERMANY.

renown VAT-DYE.

Specification of Letters Patent.

Patented. Nov. 26, 1907 Application 516a July 24.1907. Serial-1N0.385.311.

Germany, residing at Hochst-on-the-Main,-

Germany, have invented certain new and useful- Improvements 1n Making aNew Brown Vat-Dyestufi, of which the following- 1s aspecification.

I have found a new brown vat dyestufi having the formida:

alkalies, dilute acids, soluble in concentrated F -sulfuric acid with ablue color, soluble with great diificulty in hot nitrobenzene with anorange brown color; it is reduced by alkaline reducing agents, forinstance, an alkaline hy Ldyes from this solution cotton and wool indrosulfite solution to a leuco compound and brown shades.

This vat dyestuli may be obtained, 'for instance, by" heating metanmidohenylthioglycollic-ortho-carboxylic acid laying the ormular.

' coon .(6)' c n, sornooon 1 NHouoH a with'alkali hydrates and byoxidizing the leuco bodies, n1eta-amidooxythionaphthene carboxyl ic acidor meta-amidobxythionaphithene.

The parent material, for instance, themeta-acetylamldophenyltluoglycolhc acid coon g6) 0,11, sorncoon 1nnooon, a

may be obtained as follows: 110 gr. of acetaminoanthranilic acidooonmnennciuao eee i gr. of caustic soda and water and boiled for somehours. After filtration the solution is precipitated with hydrochloricacid, Where-' lic-ortho-carboxylic acid is precipitated as a yellowishowder. i

.The me t is made, for instance, as folupon themeta-acetamidophenylthioglycollows parts by weight of this acid are vintroduced at about 100 C.into 180 parts by ,weight of caustic sodaliquefied With about 30parts or more of water. The temperature isgradually raised while stirring to 170 C. till the melt becomes brittle.The condensation begins already at 130 0., at this temperature, however,more time is needed for the completion of the melt. The operation mayalso occur by using'less alkali or under pressure. The product ofcondensation may be isolated in various Ways. Thus, for instance,stirring may occur with little Water; the sodium salt ofmeta-amido-oxythionaphthene-carboxylic acid, thus separated, and solublewith diiiiculty in alkalihydrate, readily soluble in water, is filteredfrom the excess of the alkalihydrate solution. The product ofcondensation, meta-amidodxythionaphthene carboxylic acid, may also beobtained from-the aqgeons solution of the strongly cooled melt ydirectly acidiiyhig -with acetic acid, when it is precipitated as acrystalline gray powder. It is soluble in an excess of hydrochloric acidin the heat, carbonic acid being evolved on boiling, and from thehydrochlorid solution the metaainidooxythionaphthene may be precipitatedwith sodium acetate or bicarbonate as a crystalline powder, ltis solublein hot Water and crystallizes when cold. it is soluble in alkalihydrateand in an excess oi mineral acid.

The oxidation of the aims-described leuco bodies may be carried out asfollows 30 parts by weight of the above carboxylic acid or ofmeta-amidooxythionaphthone are dissolved in the heat with 30 parts byweight of soda-lye in 2000 parts by weight of water, the solution beingthen treated with air at about 7 0S0 C. till no furthermetaamidooxythionaphthene carboxylic acid can be trappd inthe filtrateof the separated dyestu.

The operation may also occur by oxidizing in a neutral or in analkalicarbonate-alkaline suspension instead of in a very dilute causticalkali solution oreveu by directly using the sodium salt ofmetaamidooxythionaphand the like in neutral or feebly alkaline solution.

The dyestuff separated in brown flakes by 5 one or the other method isisolated from the mother lye by filtration and may be purified fromsmall inter-mixtures by boiling with alcohol. When dry, it is a brownpowder,

insoluble in water, alkalies, dilute acids,

soluble in concentrated sulfuric acid with a blue color, soluble withgreat dilficulty in hot nitrobenzene with an orange-brown color ;4 1t isreduced to a leuco compound by alkaline reducing agents, for instance,an alkaline hydrosulfite solutlon and dyes from this solution cotton andWool brown shades.

saaose Haring now described my l'il.='.i1il.'i= what I claim is Asproduct, the brown vat dyostufl' having the formula:

(6 o( unffm Nimnqm o= '1 i,n im;\- 1.

S beingv insoluble in water, alkalies, dilute acids, solnbla inconcentrated sulfur; acid with a llill color, forming with alkaline fhydrosuliito a yellowish-brown n? from which wool and cotton are dyedbroivn shades.

In testimony, that I claim the foregoing as my invention, I-have signedmy name in presence ofatwo subscribing witiaos-s'vs.

' ALBRlDllll .-1(."ll.-ill)l. Wi tnesses JEAN Gnuxn CARL GRUND.

